Re: [xrblock] Burst Discard Count

Varun Singh <> Fri, 27 February 2015 11:36 UTC

Return-Path: <>
Received: from localhost ( []) by (Postfix) with ESMTP id 99D041A916C for <>; Fri, 27 Feb 2015 03:36:21 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Status: No, score=-2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, SPF_PASS=-0.001] autolearn=ham
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id Zj3GFBSZKoMt for <>; Fri, 27 Feb 2015 03:36:19 -0800 (PST)
Received: from ( [IPv6:2a00:1450:4010:c03::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id CEB671A9174 for <>; Fri, 27 Feb 2015 03:36:18 -0800 (PST)
Received: by lams18 with SMTP id s18so16909200lam.11 for <>; Fri, 27 Feb 2015 03:36:17 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; bh=zeoi+FYQ8oVRgAOGJbEv/YOQwlicOrF6NIFStdTsI0c=; b=jDgmDktSPHx8qNFnUzdBSPeEohlEGgcBWNy9L2rovsR9CuT7TiAZtl3I7sn6X5ua5N J9sD+Tbe2NdJaTrgLYNddboxatI3JKf/cfw6zHU+TCB/RbDFK8V3DQwFROUCgr49xEkB lWvoDyNL8oeeytZnPsWyEwrHHr2iElb9Rfxd0HN3bF+MYfFcVYyLPurorahiiNWu6PnP 9Nv94fo2oUdjBsk7ccB33RAh6DvHr9lbUBrgpuhBEyK3nUY7vrUnaM3oJhZ54USZZb1p yqgqO7iIdYalrzShqVC14I7jHbdPHZWUBVMxnXE+llaZkINKIHraauPyAwSahgmPxsmK 6iRA==
X-Received: by with SMTP id v20mr12020612laz.81.1425036977026; Fri, 27 Feb 2015 03:36:17 -0800 (PST)
MIME-Version: 1.0
Received: by with HTTP; Fri, 27 Feb 2015 03:35:56 -0800 (PST)
In-Reply-To: <>
References: <> <>
From: Varun Singh <>
Date: Fri, 27 Feb 2015 13:35:56 +0200
Message-ID: <>
To: Qin Wu <>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Archived-At: <>
Cc: "" <>
Subject: Re: [xrblock] Burst Discard Count
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Metric Blocks for use with RTCP's Extended Report Framework working group discussion list <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Fri, 27 Feb 2015 11:36:21 -0000

Hi Qin,

On Fri, Feb 27, 2015 at 4:05 AM, Qin Wu <> wrote:
> The argument is correct, but when the burst count for loss and burst count for discard are corresponding to the same reported source, the value for them are probably same.

To confirm, the burstCount indicates the number of intervals where
bursts occur, and not the packets in an individual bursts.

I think the implicit assumption is that losses and discards are
correlated, and that discards may occur before losses. However,
consider a congestion control algorithm that is sensitive to discards
may correct before any losses occur. Then the burstCount measuring
only losses would not increase  and hence burst discards count will
not correspond to burst loss count.

> Also burst gap discard is intended to be sent together with burst gap loss.
> See the section 1 of RFC7003:
> "
> This block is intended to be used in conjunction with [RFC7002], which provides the
> total packets discarded and on which this block therefore depends.
> However, the metric in [RFC7002] may be used independently of the
> metrics in this block.
> "
> -Qin
> -----邮件原件-----
> 发件人: xrblock [] 代表 Varun Singh
> 发送时间: 2015年2月26日 19:34
> 收件人:
> 主题: [xrblock] Burst Discard Count
> Hi all,
> While preparing the -01 version of the
> draft-ietf-xrblock-rtcweb-rtcp-xr-metrics, I noticed that the
> RFC6958 - Burst/Gap Loss reports a "burst count" metric, which indicates the number of bursts  in an reporting interval (cumulative or arbitrary time interval). However, RFC7003 does not report a corresponding burst count metric for discarded packets.
> I forget if this was discussed before, but it appears to be an oversight, as arguments for including burst count for loss also apply to burst discards -- unless I am missing something or it is defined elsewhere. How do we fix this?
> This may be non-blocking for the rtcweb metrics as we could instead use the burstLossRate and burstDiscardRate which are defined in the summary statistics in RFC7004.
> Thanks and Regards,
> Varun
> --
> _______________________________________________
> xrblock mailing list